1. Field of the Invention
The present invention relates to data management using a folder hierarchy.
2. Description of the Related Art
One data management method that is popularly used is a method for classifying data into folders. Such a method embodies a user-desired data classification system in a hierarchical folder structure where data is registered in one folder, which is then registered in another folder. Methods for building such a hierarchical folder structure are broadly divided into two categories: those where data and a folder can be registered in only a single folder (hereinafter referred to as a tree structure) and those where data and a folder can be registered in multiple folders (hereinafter referred to as a non-tree structure). Examples of conventional techniques using a tree structure include Microsoft Windows® FAT (file allocation table) and NTFS (New Technology File System). Examples of conventional techniques using a non-tree structure include a method for sharing a single folder among multiple folders (Japanese Patent Laid-open No. 11-134233) and links in a Unix® file system.
In a mixed environment of such a system using a non-tree structure and such a system using a tree structure, the hierarchical folder structure of the former system needs to be converted into a tree structure at the time of exporting data from the former to the latter. Conventional techniques for such conversion include those used by Samba, which is a software suite used to export data from Unix® to Windows® (cf., Samba org., “What Is Samba?” [online], retrieved from the Internet:<URL: http://www.samba.org/>; and Samba Users Group Japan, “What Is Samba?” [online], retrieved from the Internet: <URL: http://wiki.samba.gr.jp/mediawiki/index.php/Samba % E3%81% A8% E3%81% AF/>).
However, there are, for example, the following problems with the use of such conventional techniques at the time of exporting folders from a non-tree-structure system to a tree-structure system:
the possibility of copying duplicate data that has been registered in multiple folders to every registration target folder; and
the inability to export a folder that has been registered in multiple folders.